Solve for $z$ : $11 + z = -23$
Solution: Subtract $11$ from both sides: $ \begin{eqnarray} \\ 11 + z &=& -23 \\ \\ {-11} && {-11} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{11 + z} &\hphantom{=}& \hphantom{-23} \\ z &=& -23 {- 11} \\ \end{eqnarray} $ Simplify. $ z = -34$